TRA-1-85/CD147 8 E4 W1 V8 b& ~' a9 XThe TRA-1-85 antigen, also known as OKa blood group antigen, is a specific epitope within the protein known as basigin, EMMPRIN, or CD147. It is a cell surface determinant expressed on almost all human cell types. Antibodies to TRA-1-85 have been used in somatic cell hybrid or transplantation studies to identify tissues containing cells of human origin.